A study of thermoregulatory and emotional sweating in man by skin ion transfer

Local introduction of atropine and dibenzyline into human skin was carried out by iontophoresis. Both thermoregulatory and emotional sweating were blocked by atropine but were not blocked by dibenzyline. It would seem that emotional sweating produced as a result of a physical stress situation is partly or predominately under cholinergic control.     

p-nitrophenyl phosphate hydrolysis and calcium ion transport in fragmented sarcoplasmic reticulum

The calcium ion pump of fragmented sarcoplasmic reticulum can be coupled to hydrolysis of p-nitrophenyl phosphate, in the absence of added adenosine triphosphate. Comparison of the activities obtained with the two substrates suggests an analogous mechanism of transport. Independent of the substrate, a 2 : 1 ratio between calcium ion transport and substrate hydrolysis is displayed by the system, and an identical amount of work is required for ion transport against a given gradient. A phosphate ester appears necessary for substrate utilization in the pump mechanism, whereas the structure of the substrate determines the rates of activity and the affinity of the system for calcium ion.     

Mechanism and dynamics of ion transfer across a liquid-liquid interface

A detailed molecular model for ion transfer across the interface between water and 1,2-dichloroethane provides insight into the mechanism of the transfer across the interface between two immiscible liquids. Extensive molecular dynamics computer simulations underscore the roles of surface roughness and capillary distortions in this process, demonstrate that ion transfer is an activated rather than a simple diffusive process, and provide a test for the applicability of theoretical models.     

Phosphoryl transfer and calcium ion occlusion in the calcium pump

A tight coupling between adenosine triphosphate (ATP) hydrolysis and vectorial ion transport has to be maintained by ATP-consuming ion pumps. We report two crystal structures of Ca2+-bound sarco(endo)plasmic reticulum Ca2+-adenosine triphosphatase (SERCA) at 2.6 and 2.9 angstrom resolution in complex with (i) a nonhydrolyzable ATP analog [adenosine (beta-gamma methylene)-triphosphate] and (ii) adenosine diphosphate plus aluminum fluoride. SERCA reacts with ATP by an associative mechanism mediated by two Mg2+ ions to form an aspartyl-phosphorylated intermediate state (Ca2-E1 approximately P). The conformational changes that accompany the reaction with ATP pull the transmembrane helices 1 and 2 and close a cytosolic entrance for Ca2+, thereby preventing backflow before Ca2+ is released on the other side of the membrane.     

Side-on copper-nitrosyl coordination by nitrite reductase

A copper-nitrosyl intermediate forms during the catalytic cycle of nitrite reductase, the enzyme that mediates the committed step in bacterial denitrification. The crystal structure of a type 2 copper-nitrosyl complex of nitrite reductase reveals an unprecedented side-on binding mode in which the nitrogen and oxygen atoms are nearly equidistant from the copper cofactor. Comparison of this structure with a refined nitrite-bound crystal structure explains how coordination can change between copper-oxygen and copper-nitrogen during catalysis. The side-on copper-nitrosyl in nitrite reductase expands the possibilities for nitric oxide interactions in copper proteins such as superoxide dismutase and prions.     

First solvation shell of the Cu(II) aqua ion: evidence for fivefold coordination

We determined the structure of the hydrated Cu(II) complex by both neutron diffraction and first-principles molecular dynamics. In contrast with the generally accepted picture, which assumes an octahedrally solvated Cu(II) ion, our experimental and theoretical results favor fivefold coordination. The simulation reveals that the solvated complex undergoes frequent transformations between square pyramidal and trigonal bipyramidal configurations. We argue that this picture is also consistent with experimental data obtained previously by visible near-infrared absorption, x-ray absorption near-edge structure, and nuclear magnetic resonance methods. The preference of the Cu(II) ion for fivefold instead of sixfold coordination, which occurs for other cations of comparable charge and size, results from a Jahn-Teller destabilization of the octahedral complex.     

产多糖溶磷细菌对难溶性Ca-P的活化特性

以肠杆菌EnHy-401、节杆菌ArHy-505、固氮菌AzHy-510和巨大芽孢杆菌P17为材料,比较了4种溶磷细菌在摇瓶培养条件下对不同难溶性Ca-P中的磷活化能力.结果表明,4种溶磷细菌均能促使难溶性Ca-P中的磷活化, 但3种产多糖的溶磷细菌(EnHy-401、ArHy-505、AzHy-510)对难溶性Ca-P的活化能力普遍强于不产多糖的溶磷细菌(P17),肠杆菌EnHy-401对Ca3-P、Ca8-P和Ca10-P中的磷活化率分别达61.53%、63.40%和4.32%.在产多糖的溶磷细菌中,有机酸和多糖均高的菌株活化磷的能力最高,3种产多糖的溶磷细菌活化难溶磷酸钙能力的大小顺序依次为肠杆菌EnHy-401、节杆菌ArHy-505、固氮菌AzHy-510.结果还表明,产多糖的溶磷细菌对难溶磷的活化作用是由分泌有机酸和多糖的协同作用实现的,多糖对磷的吸持推动了磷的溶解平衡向溶解方向移动,且该协同作用受胞外多糖持磷能力和环境中C/N的影响,单位体积发酵液中多糖持磷量与菌株的磷活化能力呈正相关.在本试验条件下,C/N值高时,多糖产量高,有机酸分泌多,活化磷的能力就强.同一菌株只有在最适于产有机酸和产多糖的C/N值下,才能表现出最佳的溶磷效果.     

Mechanism of enzyme inhibition by phosphate esters

A theory for the rapid specific reaction of certain phosphorous-containing esters with many proteolytic enzymes based on the ability of phosphorous to form one additional bond relative to carbon is presented. A stable tetrahedral phosphate ester is compared with a labile tetrahedral orthocarbonyl ester and a relatively stable pentagonal enzyme-phosphate ester complex is compared with a pentagonal enzyme-carbonyl substrate complex. The latter complex is assumed to be the transition state in the enzyme-catalyzed reaction. If the theory is correct, it opens up the possibility of studying intermediates and transition states from the known structures of chemical inhibitors.     

牛膝细胞转化苗的田间培植

经过近1年的实验室工作,于1997年5月得到发育良好的牛膝细胞转化苗.1997年6月将室内培植14日的6棵幼苗移栽至田间.种植1O日后去弱保留3棵.1997年1O月收获种子.一部分留样,一部分于1998年5月进行田间播种,扩大种植.     

基于熵值法的新疆农村剩余劳动力转移影响因素耦合协调度分析

[目的]为丰富剩余劳动力转移理念,完善新疆劳动力转移政策,加大农村剩余劳动力转移规模,同步推进城镇化建设提供参考.[方法]采用熵值赋权法和耦合度、耦合协调度法,对新疆1997~2011年相关数据进行研究.[结果]从熵值赋权法结果来看,农村恩格尔系数、城镇化率、文盲率和教育财政支出4个序参量对新疆农村剩余劳动力转移的影响较显著.农村剩余劳动力转移影响因素指标体系下3个一层指标系统(经济因素系统、社会因素系统和劳动力因素系统)之间存在耦合关系,但耦合度指数较低,临近失调,且协调度长期处于衰退状态,3个一层指标系统中生产力因素对整体耦合协调度影响最大.[建议]应建立高效、平衡的农村剩余劳动力转移机制、引进先进技术、促进当地就业规模、健全农民工社会保障体系,以加快新疆农村剩余劳动力转移,推进城镇化建设.     

Spatial coordination of spindle assembly by chromosome-mediated signaling gradients

During cell division, chromosomes are distributed to daughter cells by the mitotic spindle. This system requires spatial cues to reproducibly self-organize. We report that such cues are provided by chromosome-mediated interaction gradients between the small guanosine triphosphatase (GTPase) Ran and importin-beta. This produces activity gradients that determine the spatial distribution of microtubule nucleation and stabilization around chromosomes and that are essential for the self-organization of microtubules into a bipolar spindle.     

Cognitive interaction after staged callosal section: evidence for transfer of semantic activation

Sensory and cognitive functions were assessed in a right-handed male before and after partial and complete callosal commissurotomy. After the initial posterior section was made, there was no evidence of interhemispheric sensory transfer, although the left hemisphere did have access to stimulus-related semantic and episodic information from the right hemisphere. After the callosum was completely sectioned, this exchange was no longer observed.     

Detection and examination of anthrosols by phosphate analysis

Land-use analysis of anthrosols has been performed by a new, two-part method. A rapid qualitative field test assists in locating past settlements and determining their areal and temporal extent, even where artifacts are missing. The field-test results are verified and samples are analyzed further by quantitative soil phosphate fractionation. Laboratory fractionation reveals much more than the simple phosphate test used at present. Like the chemical field test, it uses minute soil samples and may be invaluable where disturbance of the landscape is forbidden. Phosphate fractions reflect the details of man-induced changes in the soil and the timing of their appearance.     

承接产业转移背景下中西部经济发展和环境保护协调发展研究——以安徽省滁州市为例

产业梯度转移背景下,随着承接产业转移进程的加快,中西部许多地区承接产业转移时都面临着较大的潜在环境风险。课题首先分析了承接产业转移与环境潜在风险的内在关联性,并在此基础上进一步探究了各地在产业承接产业转移过程中各种环境问题频出的相关原因,最后在综合各种原因分析和国内外应对经验的基础上,以安徽省滁州市为例,提出了承接产业过程中协调经济发展和环境保护的具体路径。     

接种物对磷酸盐的厌氧转化作用

磷酸盐转化成磷化氢是一个具有重要潜在价值的生物反应.将猪粪与两种厌氧污泥按质量比3:1:1混合作为接种物,试验了纤维素、葡萄糖和乙酸作为磷酸盐还原反应电子供体的可行性.结果证明,葡萄糖是磷酸盐还原反应适宜的电子供体.以葡萄糖作为电子供体,比较了磷酸盐和次亚磷酸盐的还原情况.在等量的电子供体下,理论上次亚磷酸盐去除率应为磷酸盐去除率的2倍,实测结果与理论值相吻合.理论上所需的水合葡萄糖与磷酸二氢钾之比(质量比)约为1:2,实际适宜的水合葡萄糖与磷酸二氢钾之比为1:1.检测发现,磷去除率与碱液吸收磷浓度变化具有较好的相关性,与硫酸盐还原菌数量也有一定的相关性,但与发酵菌的数量没有明显的相关性.